From a21b83b1271884e6f08507d4734440a0349f71d1 Mon Sep 17 00:00:00 2001 From: Janez T Date: Sun, 8 Mar 2026 14:14:26 +0100 Subject: [PATCH] fix: address comments ref: --- docs/companion_protocol.md | 65 ++++++++++++++++++++++------- examples/companion_radio/MyMesh.cpp | 37 +++++++++------- examples/companion_radio/MyMesh.h | 2 +- src/MeshCore.h | 3 +- src/helpers/BaseChatMesh.cpp | 44 ++++++++++++------- src/helpers/BaseChatMesh.h | 4 +- src/helpers/TxtDataHelpers.h | 2 +- 7 files changed, 107 insertions(+), 50 deletions(-) diff --git a/docs/companion_protocol.md b/docs/companion_protocol.md index bf030bfa..c00be4a2 100644 --- a/docs/companion_protocol.md +++ b/docs/companion_protocol.md @@ -291,17 +291,21 @@ Bytes 7+: UTF-8 text bytes (variable length) **Command Format**: ``` Byte 0: 0x3E -Byte 1: Data Type (`txt_type`) +Byte 1: Data Type (`data_type`) Byte 2: Channel Index (0-7) Bytes 3-6: Timestamp (32-bit little-endian Unix timestamp, seconds) Bytes 7+: Binary payload bytes (variable length) ``` **Data Type / Transport Mapping**: -- `0xFF` (`TXT_TYPE_CUSTOM_BINARY`) must be used for custom-protocol binary datagrams. +- `0xFF` (`DATA_TYPE_CUSTOM`) must be used for custom-protocol binary datagrams. - `0x00` (`TXT_TYPE_PLAIN`) is invalid for this command. - Values other than `0xFF` are reserved for official protocol extensions. +**Limits**: +- Maximum payload length is `163` bytes (`MAX_GROUP_DATA_LENGTH`). +- Larger payloads are rejected with `PACKET_ERROR` / `ERR_CODE_ILLEGAL_ARG`. + **Response**: `PACKET_OK` (0x00) on success --- @@ -322,6 +326,7 @@ Byte 0: 0x0A **Response**: - `PACKET_CHANNEL_MSG_RECV` (0x08) or `PACKET_CHANNEL_MSG_RECV_V3` (0x11) for channel messages +- `PACKET_CHANNEL_DATA_RECV` (0x1B) or `PACKET_CHANNEL_DATA_RECV_V3` (0x1C) for channel data - `PACKET_CONTACT_MSG_RECV` (0x07) or `PACKET_CONTACT_MSG_RECV_V3` (0x10) for contact messages - `PACKET_NO_MORE_MSGS` (0x0A) if no messages available @@ -391,11 +396,15 @@ Messages are received via the TX characteristic (notifications). The device send - `PACKET_CHANNEL_MSG_RECV` (0x08) - Standard format - `PACKET_CHANNEL_MSG_RECV_V3` (0x11) - Version 3 with SNR -2. **Contact Messages**: +2. **Channel Data**: + - `PACKET_CHANNEL_DATA_RECV` (0x1B) - Standard format + - `PACKET_CHANNEL_DATA_RECV_V3` (0x1C) - Version 3 with SNR + +3. **Contact Messages**: - `PACKET_CONTACT_MSG_RECV` (0x07) - Standard format - `PACKET_CONTACT_MSG_RECV_V3` (0x10) - Version 3 with SNR -3. **Notifications**: +4. **Notifications**: - `PACKET_MESSAGES_WAITING` (0x83) - Indicates messages are queued ### Contact Message Format @@ -489,37 +498,62 @@ Bytes 11+: Payload bytes **Payload Meaning**: - If `txt_type == 0x00`: payload is UTF-8 channel text. - If `txt_type != 0x00`: payload is binary (for example image/voice fragments) and must be treated as raw bytes. - For custom app datagrams sent via `CMD_SEND_CHANNEL_DATA`, `txt_type` must be `0xFF`. + For custom app datagrams sent via `CMD_SEND_CHANNEL_DATA`, `data_type` must be `0xFF`. + +### Channel Data Format + +**Standard Format** (`PACKET_CHANNEL_DATA_RECV`, 0x1B): +``` +Byte 0: 0x1B (packet type) +Byte 1: Channel Index (0-7) +Byte 2: Path Length +Byte 3: Data Type +Bytes 4-7: Timestamp (32-bit little-endian) +Bytes 8+: Payload bytes +``` + +**V3 Format** (`PACKET_CHANNEL_DATA_RECV_V3`, 0x1C): +``` +Byte 0: 0x1C (packet type) +Byte 1: SNR (signed byte, multiplied by 4) +Bytes 2-3: Reserved +Byte 4: Channel Index (0-7) +Byte 5: Path Length +Byte 6: Data Type +Bytes 7-10: Timestamp (32-bit little-endian) +Bytes 11+: Payload bytes +``` **Parsing Pseudocode**: ```python -def parse_channel_message(data): +def parse_channel_frame(data): packet_type = data[0] offset = 1 # Check for V3 format - if packet_type == 0x11: # V3 + if packet_type in (0x11, 0x1C): # V3 snr_byte = data[offset] snr = ((snr_byte if snr_byte < 128 else snr_byte - 256) / 4.0) offset += 3 # Skip SNR + reserved channel_idx = data[offset] path_len = data[offset + 1] - txt_type = data[offset + 2] + item_type = data[offset + 2] timestamp = int.from_bytes(data[offset+3:offset+7], 'little') payload = data[offset+7:] - if txt_type == 0: + is_text = packet_type in (0x08, 0x11) + if is_text and item_type == 0: message = payload.decode('utf-8') else: message = None return { 'channel_idx': channel_idx, - 'txt_type': txt_type, + 'item_type': item_type, 'timestamp': timestamp, 'payload': payload, 'message': message, - 'snr': snr if packet_type == 0x11 else None + 'snr': snr if packet_type in (0x11, 0x1C) else None } ``` @@ -556,6 +590,8 @@ Use `CMD_SEND_CHANNEL_TXT_MSG` for plain text, and `CMD_SEND_CHANNEL_DATA` for b | 0x10 | PACKET_CONTACT_MSG_RECV_V3 | Contact message (V3 with SNR) | | 0x11 | PACKET_CHANNEL_MSG_RECV_V3 | Channel message (V3 with SNR) | | 0x12 | PACKET_CHANNEL_INFO | Channel information | +| 0x1B | PACKET_CHANNEL_DATA_RECV | Channel data (standard) | +| 0x1C | PACKET_CHANNEL_DATA_RECV_V3| Channel data (V3 with SNR) | | 0x80 | PACKET_ADVERTISEMENT | Advertisement packet | | 0x82 | PACKET_ACK | Acknowledgment | | 0x83 | PACKET_MESSAGES_WAITING | Messages waiting notification | @@ -775,7 +811,7 @@ BLE implementations enqueue and deliver one protocol frame per BLE write/notific - `SET_CHANNEL` → `PACKET_OK` or `PACKET_ERROR` - `CMD_SEND_CHANNEL_TXT_MSG` → `PACKET_OK` or `PACKET_ERROR` - `CMD_SEND_CHANNEL_DATA` → `PACKET_OK` or `PACKET_ERROR` - - `GET_MESSAGE` → `PACKET_CHANNEL_MSG_RECV`, `PACKET_CONTACT_MSG_RECV`, or `PACKET_NO_MORE_MSGS` + - `GET_MESSAGE` → `PACKET_CHANNEL_MSG_RECV`, `PACKET_CHANNEL_DATA_RECV`, `PACKET_CONTACT_MSG_RECV`, or `PACKET_NO_MORE_MSGS` - `GET_BATTERY` → `PACKET_BATTERY` 4. **Timeout Handling**: @@ -855,8 +891,9 @@ response = wait_for_response(PACKET_OK) def on_notification_received(data): packet_type = data[0] - if packet_type == PACKET_CHANNEL_MSG_RECV or packet_type == PACKET_CHANNEL_MSG_RECV_V3: - message = parse_channel_message(data) + if packet_type in (PACKET_CHANNEL_MSG_RECV, PACKET_CHANNEL_MSG_RECV_V3, + PACKET_CHANNEL_DATA_RECV, PACKET_CHANNEL_DATA_RECV_V3): + message = parse_channel_frame(data) handle_channel_message(message) elif packet_type == PACKET_MESSAGES_WAITING: # Poll for messages diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp index 85df464f..490f34a1 100644 --- a/examples/companion_radio/MyMesh.cpp +++ b/examples/companion_radio/MyMesh.cpp @@ -92,6 +92,8 @@ #define RESP_CODE_STATS 24 // v8+, second byte is stats type #define RESP_CODE_AUTOADD_CONFIG 25 #define RESP_ALLOWED_REPEAT_FREQ 26 +#define RESP_CODE_CHANNEL_DATA_RECV 27 +#define RESP_CODE_CHANNEL_DATA_RECV_V3 28 #define SEND_TIMEOUT_BASE_MILLIS 500 #define FLOOD_SEND_TIMEOUT_FACTOR 16.0f @@ -205,7 +207,8 @@ void MyMesh::updateContactFromFrame(ContactInfo &contact, uint32_t& last_mod, co } bool MyMesh::Frame::isChannelMsg() const { - return buf[0] == RESP_CODE_CHANNEL_MSG_RECV || buf[0] == RESP_CODE_CHANNEL_MSG_RECV_V3; + return buf[0] == RESP_CODE_CHANNEL_MSG_RECV || buf[0] == RESP_CODE_CHANNEL_MSG_RECV_V3 || + buf[0] == RESP_CODE_CHANNEL_DATA_RECV || buf[0] == RESP_CODE_CHANNEL_DATA_RECV_V3; } void MyMesh::addToOfflineQueue(const uint8_t frame[], int len) { @@ -565,27 +568,30 @@ void MyMesh::onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packe #endif } -void MyMesh::onChannelDataRecv(const mesh::GroupChannel &channel, mesh::Packet *pkt, uint32_t timestamp, uint8_t txt_type, +void MyMesh::onChannelDataRecv(const mesh::GroupChannel &channel, mesh::Packet *pkt, uint32_t timestamp, uint8_t data_type, const uint8_t *data, size_t data_len) { int i = 0; if (app_target_ver >= 3) { - out_frame[i++] = RESP_CODE_CHANNEL_MSG_RECV_V3; + out_frame[i++] = RESP_CODE_CHANNEL_DATA_RECV_V3; out_frame[i++] = (int8_t)(pkt->getSNR() * 4); out_frame[i++] = 0; // reserved1 out_frame[i++] = 0; // reserved2 } else { - out_frame[i++] = RESP_CODE_CHANNEL_MSG_RECV; + out_frame[i++] = RESP_CODE_CHANNEL_DATA_RECV; } uint8_t channel_idx = findChannelIdx(channel); out_frame[i++] = channel_idx; out_frame[i++] = pkt->isRouteFlood() ? pkt->path_len : 0xFF; - out_frame[i++] = txt_type; + out_frame[i++] = data_type; memcpy(&out_frame[i], ×tamp, 4); i += 4; size_t available = MAX_FRAME_SIZE - i; - if (data_len > available) data_len = available; + if (data_len > available) { + MESH_DEBUG_PRINTLN("onChannelDataRecv(): payload_len=%d exceeds frame space=%d, truncating", (uint32_t)data_len, (uint32_t)available); + data_len = available; + } int copy_len = (int)data_len; if (copy_len > 0) { memcpy(&out_frame[i], data, copy_len); @@ -1069,29 +1075,27 @@ void MyMesh::handleCmdFrame(size_t len) { } } else if (cmd_frame[0] == CMD_SEND_CHANNEL_TXT_MSG) { // send GroupChannel text msg int i = 1; - uint8_t txt_type = cmd_frame[i++]; + uint8_t txt_type = cmd_frame[i++]; // should be TXT_TYPE_PLAIN uint8_t channel_idx = cmd_frame[i++]; uint32_t msg_timestamp; memcpy(&msg_timestamp, &cmd_frame[i], 4); i += 4; const char *text = (char *)&cmd_frame[i]; - int text_len = (len > (size_t)i) ? (int)(len - i) : 0; if (txt_type != TXT_TYPE_PLAIN) { writeErrFrame(ERR_CODE_UNSUPPORTED_CMD); } else { ChannelDetails channel; - if (!getChannel(channel_idx, channel)) { - writeErrFrame(ERR_CODE_NOT_FOUND); // bad channel_idx - } else if (sendGroupMessage(msg_timestamp, channel.channel, _prefs.node_name, text, text_len)) { + bool success = getChannel(channel_idx, channel); + if (success && sendGroupMessage(msg_timestamp, channel.channel, _prefs.node_name, text, len - i)) { writeOKFrame(); } else { - writeErrFrame(ERR_CODE_TABLE_FULL); + writeErrFrame(ERR_CODE_NOT_FOUND); // bad channel_idx } } } else if (cmd_frame[0] == CMD_SEND_CHANNEL_DATA) { // send GroupChannel datagram int i = 1; - uint8_t txt_type = cmd_frame[i++]; + uint8_t data_type = cmd_frame[i++]; uint8_t channel_idx = cmd_frame[i++]; uint32_t msg_timestamp; memcpy(&msg_timestamp, &cmd_frame[i], 4); @@ -1102,9 +1106,12 @@ void MyMesh::handleCmdFrame(size_t len) { ChannelDetails channel; if (!getChannel(channel_idx, channel)) { writeErrFrame(ERR_CODE_NOT_FOUND); // bad channel_idx - } else if (txt_type != TXT_TYPE_CUSTOM_BINARY) { + } else if (data_type != DATA_TYPE_CUSTOM) { writeErrFrame(ERR_CODE_UNSUPPORTED_CMD); - } else if (sendGroupData(msg_timestamp, channel.channel, txt_type, payload, payload_len)) { + } else if (payload_len > MAX_GROUP_DATA_LENGTH) { + MESH_DEBUG_PRINTLN("CMD_SEND_CHANNEL_DATA payload too long: %d > %d", payload_len, MAX_GROUP_DATA_LENGTH); + writeErrFrame(ERR_CODE_ILLEGAL_ARG); + } else if (sendGroupData(msg_timestamp, channel.channel, data_type, payload, payload_len)) { writeOKFrame(); } else { writeErrFrame(ERR_CODE_TABLE_FULL); diff --git a/examples/companion_radio/MyMesh.h b/examples/companion_radio/MyMesh.h index 0e112647..78ea6414 100644 --- a/examples/companion_radio/MyMesh.h +++ b/examples/companion_radio/MyMesh.h @@ -137,7 +137,7 @@ protected: const uint8_t *sender_prefix, const char *text) override; void onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packet *pkt, uint32_t timestamp, const char *text) override; - void onChannelDataRecv(const mesh::GroupChannel &channel, mesh::Packet *pkt, uint32_t timestamp, uint8_t txt_type, + void onChannelDataRecv(const mesh::GroupChannel &channel, mesh::Packet *pkt, uint32_t timestamp, uint8_t data_type, const uint8_t *data, size_t data_len) override; uint8_t onContactRequest(const ContactInfo &contact, uint32_t sender_timestamp, const uint8_t *data, diff --git a/src/MeshCore.h b/src/MeshCore.h index 70cd0f06..3eb4f935 100644 --- a/src/MeshCore.h +++ b/src/MeshCore.h @@ -17,6 +17,7 @@ #define PATH_HASH_SIZE 1 #define MAX_PACKET_PAYLOAD 184 +#define MAX_GROUP_DATA_LENGTH (MAX_PACKET_PAYLOAD - CIPHER_BLOCK_SIZE - 5) #define MAX_PATH_SIZE 64 #define MAX_TRANS_UNIT 255 @@ -100,4 +101,4 @@ public: } }; -} \ No newline at end of file +} diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp index e6f59a50..d8e089d5 100644 --- a/src/helpers/BaseChatMesh.cpp +++ b/src/helpers/BaseChatMesh.cpp @@ -353,10 +353,18 @@ int BaseChatMesh::searchChannelsByHash(const uint8_t* hash, mesh::GroupChannel d #endif void BaseChatMesh::onGroupDataRecv(mesh::Packet* packet, uint8_t type, const mesh::GroupChannel& channel, uint8_t* data, size_t len) { - if (len < 5) return; + if (len < 5) { + MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping short group payload len=%d", (uint32_t)len); + return; + } + + uint8_t data_type = data[4]; + if (type == PAYLOAD_TYPE_GRP_TXT) { + if ((data_type >> 2) != 0) { + MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping unsupported group text type=%d", (uint32_t)data_type); + return; + } - uint8_t txt_type = data[4]; - if (type == PAYLOAD_TYPE_GRP_TXT && (txt_type >> 2) == 0) { // 0 = plain text msg uint32_t timestamp; memcpy(×tamp, data, 4); @@ -368,7 +376,7 @@ void BaseChatMesh::onGroupDataRecv(mesh::Packet* packet, uint8_t type, const mes } else if (type == PAYLOAD_TYPE_GRP_DATA) { uint32_t timestamp; memcpy(×tamp, data, 4); - onChannelDataRecv(channel, packet, timestamp, txt_type, &data[5], len - 5); + onChannelDataRecv(channel, packet, timestamp, data_type, &data[5], len - 5); } } @@ -460,24 +468,28 @@ bool BaseChatMesh::sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& chan return false; } -bool BaseChatMesh::sendGroupData(uint32_t timestamp, mesh::GroupChannel& channel, uint8_t txt_type, const uint8_t* data, int data_len) { - if (data_len < 0) return false; - // createGroupDatagram() accepts at most (MAX_PACKET_PAYLOAD - CIPHER_BLOCK_SIZE) - // plaintext bytes; subtract our 5-byte {timestamp, txt_type} header. - const int max_group_data_len = (MAX_PACKET_PAYLOAD - CIPHER_BLOCK_SIZE) - 5; - if (data_len > max_group_data_len) data_len = max_group_data_len; +bool BaseChatMesh::sendGroupData(uint32_t timestamp, mesh::GroupChannel& channel, uint8_t data_type, const uint8_t* data, int data_len) { + if (data_len < 0) { + MESH_DEBUG_PRINTLN("sendGroupData: invalid negative data_len=%d", data_len); + return false; + } + if (data_len > MAX_GROUP_DATA_LENGTH) { + MESH_DEBUG_PRINTLN("sendGroupData: data_len=%d exceeds max=%d", data_len, MAX_GROUP_DATA_LENGTH); + return false; + } - uint8_t temp[MAX_PACKET_PAYLOAD]; + uint8_t temp[5 + MAX_GROUP_DATA_LENGTH]; memcpy(temp, ×tamp, 4); - temp[4] = txt_type; + temp[4] = data_type; if (data_len > 0) memcpy(&temp[5], data, data_len); auto pkt = createGroupDatagram(PAYLOAD_TYPE_GRP_DATA, channel, temp, 5 + data_len); - if (pkt) { - sendFloodScoped(channel, pkt); - return true; + if (pkt == NULL) { + MESH_DEBUG_PRINTLN("sendGroupData: unable to create group datagram, data_len=%d", data_len); + return false; } - return false; + sendFloodScoped(channel, pkt); + return true; } bool BaseChatMesh::shareContactZeroHop(const ContactInfo& contact) { diff --git a/src/helpers/BaseChatMesh.h b/src/helpers/BaseChatMesh.h index 02b2dfab..12fcb957 100644 --- a/src/helpers/BaseChatMesh.h +++ b/src/helpers/BaseChatMesh.h @@ -111,7 +111,7 @@ protected: virtual uint32_t calcDirectTimeoutMillisFor(uint32_t pkt_airtime_millis, uint8_t path_len) const = 0; virtual void onSendTimeout() = 0; virtual void onChannelMessageRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint32_t timestamp, const char *text) = 0; - virtual void onChannelDataRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint32_t timestamp, uint8_t txt_type, + virtual void onChannelDataRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint32_t timestamp, uint8_t data_type, const uint8_t* data, size_t data_len) {} virtual uint8_t onContactRequest(const ContactInfo& contact, uint32_t sender_timestamp, const uint8_t* data, uint8_t len, uint8_t* reply) = 0; virtual void onContactResponse(const ContactInfo& contact, const uint8_t* data, uint8_t len) = 0; @@ -150,7 +150,7 @@ public: int sendMessage(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& expected_ack, uint32_t& est_timeout); int sendCommandData(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& est_timeout); bool sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& channel, const char* sender_name, const char* text, int text_len); - bool sendGroupData(uint32_t timestamp, mesh::GroupChannel& channel, uint8_t txt_type, const uint8_t* data, int data_len); + bool sendGroupData(uint32_t timestamp, mesh::GroupChannel& channel, uint8_t data_type, const uint8_t* data, int data_len); int sendLogin(const ContactInfo& recipient, const char* password, uint32_t& est_timeout); int sendAnonReq(const ContactInfo& recipient, const uint8_t* data, uint8_t len, uint32_t& tag, uint32_t& est_timeout); int sendRequest(const ContactInfo& recipient, uint8_t req_type, uint32_t& tag, uint32_t& est_timeout); diff --git a/src/helpers/TxtDataHelpers.h b/src/helpers/TxtDataHelpers.h index 0fbbd253..a853a64d 100644 --- a/src/helpers/TxtDataHelpers.h +++ b/src/helpers/TxtDataHelpers.h @@ -6,7 +6,7 @@ #define TXT_TYPE_PLAIN 0 // a plain text message #define TXT_TYPE_CLI_DATA 1 // a CLI command #define TXT_TYPE_SIGNED_PLAIN 2 // plain text, signed by sender -#define TXT_TYPE_CUSTOM_BINARY 0xFF // custom app binary payload (group/channel datagrams) +#define DATA_TYPE_CUSTOM 0xFF // custom app binary payload (group/channel datagrams) class StrHelper { public: